Sorry, but this is not a scientific article, this is a report about DeepMind and they works and results.
Moreover it is inaccurate because AlphaZero do not start its learning from zero but it was feeded a lot of high quality human chess games before the self training. In this manner AlphaZero got a good quality specialized opening book but Stockfish did not use any opening book during tests and its hash table was only 1GB - instead of 64GB as normally used.
Another very important difference between Stockfish and AlphaZero is Stockfish does not preserve its games but AlphaZero has an incredible huge memory to preserve its "experience".
I think the difference between the power of AlphaZero's hardware and whichever hardware of chess engines is so huge that it is very incorrect any comparison between them. A comparison based on the position per seconds is very misleading because working of Stockfish and working of AplhaZero is different fundamentally.